Blue Bird servos...... depending on if you are lucky or not.... I used 2 before on exact the same car and one just died after 3 times of play day (it was on a CRT 1/8 Truggy as steering) and the other is still working after more than 20 times of play day...
But my suggestion, get a Hitec, more reliable..
I agree with all the above comments, only some addition:
I used the 621MG for steering for my Savage X,
and it died within the first 30 MINS of play.
It just "blew" and no more response afterwards.
I am still using the 630MG for throttle for my Savage X,
and no problems YET.
I guess it's the steering bumps from the Savage that killed the Bluebird steering servo.
But its movements and jutters are really strange.
I agree with Mike,
better to go with the more reliable HITECs.
At least don't get the servos for steering, they'll die sooner than your battery =)